My dad own a 1996 E-150 with the W351. The thermostat stuck a few months back and caused overheating, and without notifying me managed to damage a head gasket. A few buddies and myself decided to make this a project and do a complete rebuild.

Anyway we have the van back together completely now, solved a few minor leaks that we had and today have been a driving it a few days. With temps in the 40-50s, i didnt think overheating would be an issue. So over the last two days ive watched it go thru heat cycles, watching the temp gauge drop a little to show the thermostat opening ect. So today i decided to take it on the highway, and gradually over a few miles the temp gauge went up, and continued to until i got off the highway miles down with the gauge between the A-L of "NORMAL", so about 3/4 of the way.

Now i know this isnt overheating, but its definetly hotter than it ran before, and im thinking with more miles on the h-way, it would have kept going up. So i got off the highway, and it gradually cooled down and i noticed the heat cycles starting up again, and operating normal. Then back on the highway and same thing, temp back up. I got off the highway to head back to the shop i work at to check for leaks and on the way the temp dropped some, but not all the way back down at a little under half way. Then after parking and letting it run, the temp went back down to normal and is cycling back and forth now completely normally. I am totally stumped, and im praying to God this isnt another breach somewhere causing air in the system.

BTW-the heads were decked ect at machine shop, also we did complete bottom end rebuild. Also replaced water pump.

My dad own a 1996 E-150 with the W351. The thermostat stuck a few months back and caused overheating, and without notifying me managed to damage a head gasket. A few buddies and myself decided to make this a project and do a complete rebuild.

Anyway we have the van back together completely now, solved a few minor leaks that we had and today have been a driving it a few days. With temps in the 40-50s, i didnt think overheating would be an issue. So over the last two days ive watched it go thru heat cycles, watching the temp gauge drop a little to show the thermostat opening ect. So today i decided to take it on the highway, and gradually over a few miles the temp gauge went up, and continued to until i got off the highway miles down with the gauge between the A-L of "NORMAL", so about 3/4 of the way.

Now i know this isnt overheating, but its definetly hotter than it ran before, and im thinking with more miles on the h-way, it would have kept going up. So i got off the highway, and it gradually cooled down and i noticed the heat cycles starting up again, and operating normal. Then back on the highway and same thing, temp back up. I got off the highway to head back to the shop i work at to check for leaks and on the way the temp dropped some, but not all the way back down at a little under half way. Then after parking and letting it run, the temp went back down to normal and is cycling back and forth now completely normally. I am totally stumped, and im praying to God this isnt another breach somewhere causing air in the system.

BTW-the heads were decked ect at machine shop, also we did complete bottom end rebuild. Also replaced water pump.

Any questions to assist in helping, please ask.

TIA
Dan

any chance the radiator is blocking up, how clean was your cooling system before the rebuild?, how long was the radiator sitting with no water in it( internal mud build up drys and blocks cores).? take the lower hose off and do a quik flow/drop test( you can do this by putting your hand over lower hose outlet and filling radiator and seeing how long it takes to rush out once you release your hand after it is full). it does sound like a radiator related problem as this is a common symptom of blocked radiator on a highway. other than that if cooling system is ok i would be looking at timing issues? hope this helps

Not to insult your intelligence, but it's easy to install a fan backwards. Can you feel the air being blown across the motor?

No offense taken there, any question or comment is more than welcome. Yes the fan is installed correctly, when standing in front of it before the grill went in, my work shirt got sucked against the radiator.

Quote:

Originally Posted by reece1

any chance the radiator is blocking up, how clean was your cooling system before the rebuild?, how long was the radiator sitting with no water in it( internal mud build up drys and blocks cores).? take the lower hose off and do a quik flow/drop test( you can do this by putting your hand over lower hose outlet and filling radiator and seeing how long it takes to rush out once you release your hand after it is full). it does sound like a radiator related problem as this is a common symptom of blocked radiator on a highway. other than that if cooling system is ok i would be looking at timing issues? hope this helps

The radiator has definetly crossed my mind. It sat empty for about 2 weeks before getting reinstalled. I was thinking of trying no thermostat, if it still does it i can eliminate t-stat, then looking into radiator, unless im encouraged otherwise.

Does this sound like a head/air in system problem? I know when we had the head gasket issue before it would overheat at any speed, even idling, and now its just at higher speeds. This is one of the most frustrating things ive ever experienced, and i would love nothing more than to be able to forget about this van for a while, i appreciate your replies, any more thoughts are more than welcome.

As far as timing, we had some timing issues right after initial startup and temps were raising at idle. We then adjusted timing to 10 degrees and the idle smoothed out huge and temps stayed normal. I dont get it, i can let it run for 3 hours outside in the driveway, but the minute im on the freeway, im toasted.

look into the radiator and do the simple test then. and we will go from there. was the water in radiator dirty?

Its so hard to tell becuase we flushed new coolant in there so many times becuase we thought we just had an air bubble before and just did that for a couple hours. I didnt see the original coolant come out, one of my techs took it out.

When the radiator was out, i cleaned the outside with a hose and flushed the inside out. I mean when the hose was on top, water came out the bottom like it should, but how do i know it was fast enough?

As far as timing, we had some timing issues right after initial startup and temps were raising at idle. We then adjusted timing to 10 degrees and the idle smoothed out huge and temps stayed normal. I dont get it, i can let it run for 3 hours outside in the driveway, but the minute im on the freeway, im toasted.

Dan

Is there a spring in the bottom hose ? Bottom hose can collapse without it at higher rpm cutting off coolant flow yet will idle all day when the hose relaxes and allows the coolant to flow.

Is there a spring in the bottom hose ? Bottom hose can collapse without it at higher rpm cutting off coolant flow yet will idle all day when the hose relaxes and allows the coolant to flow.

just a thaught

The lower radiator did have a spring in it. When i pulled that hose off during the removed of the engine process, the spring had come apart in a few pieces, and i dont believe there is any spring left in that lower hose.

Dan

EDIT: so now i called 2 Ford dealers and a Carquest, none of them have any idea about a spring in the lower hose, and one of the dealers doesnt even show that there is a oil cooler branching from that line. This is rediculous.

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